running into a flooding problem with a stihl ms 170

[Outdoorguy1979]

so I inherited my my uncles ms 170 that set for 8 years with gas in it and I desided to rebuild it, I put a new carb on it also nd it runs fine. so
I rebuild another ms 170 I had laying around and took off the carb from my other ms170 and that saw runs good.
anyway I buy a new carb for my first saw and it wants to flood out I replace that carb and it still does it.

I could use advise on what it could be it has a new fuel line and fuel filter and intake boot

 

[Maintenance supervisor]

Are you getting sufficient spark? New carb from where?

 

[Outdoorguy1979]

the carb is a c1Q S57h carb and both carbs came from stihl i am getting spark but enough spark im not sure of

 

[Maintenance supervisor]

the carb is a c1Q S57h carb and both carbs came from stihl i am getting spark but enough spark im not sure of

Yeah the flooding could be just that, it the plug isn't lighting it off you just keep dumping fuel in.
Most auto parts stores carry an inline spark tester.
Might want to pull the muffler and check out the cylinder too.

 

[Outdoorguy1979]

so update if the engine is warm it will fire right up in not just floods out

 

[rupedoggy]

I know this sounds like a dumb question but, what do you call flooding out? What does the saw do to give the idea that it is flooded? If flooded it will have a very wet spark plug. How did you get it started when it was flooded so that it starts OK when it is warm? I just don't know how much experience you have. Some people think the saw is flooded when it boggs out because of lack of fuel. Give me more info and I will try to help. BTW some of those 017 etc have a reverse thread on the adjustment screw. Turning clockwise actually riches the idle/low speed circuit.

 

[anlrolfe]

Slightly differant but, same general family.
I've got an MS170 rebuilt with Chi-Com 180 engine and replacement carb. It does something akin to flooding but partly operator induced.
It is very difficult to hear the "First POP" when I'm cold starting. Not hearing or feeling that attempt to fire, I just keep cranking and there I am, wet and soggy plug.
Something about this saw setup just makes it particular to start. It runs fine and pulls as good as expected.
I've gotten to realize to take it off choke regardless after a few pulls. I'll try a couple on high idle then flip back to choke alternating Choke/High-idle. Is this what you're supposed to do, No, but it works on this saw for me and for whatever gremlins are let loose in the carb.
I suspect that the larger than normal carb, fully adjustable H/L paired with the quality of the Chinesium engine are at the center of my particular issues.
All that said, a used rebuilt MS170/180 is a nice little saw.
Best MODIFICATION for these little saws is to add an ms250 side bar adjuster mechanism.

 

[Outdoorguy1979]

ok so when i try and start the saw there is no burp so i only pull the start rope 3 times from cold start. i then bring up the choke i notch and pull till it floods. i have replaced the carb once already and still the same thing. it has good compression i just rebuilt the saw not long ago also. my stihl mechanic is stumped. someone on another sight said its the needle jet there .45 and to replace the jet with a .75 and that would fix it but cant find any info on it.

 

[Outdoorguy1979]

it will not start when cold exept if i shoot either down the carb and i know thats a big no no but one it warms up it will start and run fine while hot

 

[rupedoggy]

My opinion.... It is not flooding.

 

[lone wolf]

Here is how I start most of my saws, full choke on with open throttle and drop start with chain brake off.

 

[Outdoorguy1979]

im just stumped why it will not start when cold

 

[HarleyT]

im just stumped why it will not start when cold

Take off the top cover and work the throttle control lever while watching. Make sure that the choke closes all the way.

 

[Dennis Gauge]

Nothing you've said so far would lead me to believe it's flooded.

When cold starting you pull with full choke until the engine pops the first time. It could take anywhere from one pull to a dozen.

To me it sounds like you're coming off full choke too soon.

Spraying with ether adds MORE fuel, and should flood it worse, not make it start.

 

[Outdoorguy1979]

im at a loss it still wont start when cold, ive had it to a stihl mechanic and even he is at a loss. so im going to take it to another stihl mechanic and see if this one can figure it out.

 

[Outdoorguy1979]

and the carb is closing all the way